Rosa Rubicondior: Creationism Refuted - British Fallow Deer Have LOST Genetic Diversity

Fallow deer

Photo credit: Memurubu, CC BY 4.0, via Wikimedia Commons

UP News - University of Potsdam

A paper just published in iScience should, if they were aware of it, at least cause an honest creationist to question some basic assumptions. It reports that modern European fallow deer, Dama dama, retain only a fraction of the genetic diversity present in their Ice Age ancestors. This finding is based on ancient DNA recovered from the fossilised remains of ten, approximately 120,000-year-old fallow deer from Neumark-Nord in Germany, analysed by researchers from the University of Potsdam, the MONREPOS Research Center and Museum in Neuwied, and Leiden University in the Netherlands.

Creationism continues to take a battering in the world of real science, where yet another paper quite incidentally refutes several of its basic dogmas. Creationists, who are notoriously reluctant to read serious science and would probably struggle to understand it if they did, will no doubt remain blissfully unaware of this constant refutation of their core superstitions.

To ensure that ignorance is maintained, creationist disinformation sites expend considerable effort in spreading distrust of serious science amongst their followers. What cult leader would want his followers reading anything that exposes his claims as bogus?

However, ignoring the facts does not make them go away, and the facts this paper reveals go to the heart of creationist mythology. Firstly, this evidence should not exist at all if the Bible creation myth were real history: a magical creation just 6,000-10,000 years ago, followed by a catastrophic global genocide, would leave no room for a 120,000-year-old population of fallow deer preserved in an Eemian lake environment. Secondly, it undermines the creationist parody of evolution that they so often attack: the false claim that evolution must always mean increasing complexity, and that any loss of genetic information is invariably fatal.

The reduced genetic diversity of modern fallow deer is a clear example of evolution involving a loss of genetic variation within a population. So far as individual deer are concerned, there need be no immediate reduction in fitness; the problem comes when a population has less capacity to respond to environmental change, disease, or other selective pressures, and may then be more vulnerable to extinction. Evolution, of course, has no plan. Unlike intelligent design, or even guided evolution, it cannot foresee future conditions and prepare a species for them. A species can be driven towards extinction by the simple operation of mindless natural processes.

British Fallow Deer and the Founder Effect. Fallow deer, Dama dama, are now a familiar part of the British countryside, but they are not truly native to Britain. They were first brought here during the Roman period, probably as ornamental animals kept in enclosed parks, or vivaria. However, genetic evidence indicates that those Roman fallow deer died out in Britain after the collapse of Roman rule.

The present British population appears to derive mainly from animals reintroduced in the 11th century, this time from the eastern Mediterranean. At first they were kept as rare and prestigious animals in aristocratic deer parks, valued both for display and for venison. As deer parks became less fashionable, and as some parks fell into disrepair, escapees and released animals formed the basis of the free-living British fallow deer population seen today.

This history provides a good example of the founder effect. When a new population is started by a small number of individuals, it carries only a sample of the genetic diversity present in the larger source population. Some alleles may be missing altogether, while others may become common simply because they happened to be present in the founders. This is not because they were necessarily better or worse, but because chance plays a much larger role in small populations.

Once isolated, such a population can lose still more variation through genetic drift: random changes in allele frequencies from one generation to the next. A population may thrive numerically while still being genetically impoverished. The danger is not always immediate poor fitness, but reduced evolutionary flexibility. If disease, climate change, habitat change, or a new parasite imposes a fresh selective pressure, a genetically narrow population may have fewer variants on which natural selection can act.

This is why the fallow deer story is so awkward for creationism. It shows evolution operating without foresight, plan, or direction. A species can become abundant while also losing genetic diversity, not because anything intended that outcome, but because population history, isolation, chance, and selection act blindly on whatever variation happens to be available.

The paper in iScience is accompanied by a news item from Potsdam University:

120,000-year-old European fallow deer – Tracing the loss of genetic diversity
European fallow deer faced a dramatic loss of genetic diversity since the last interglacial period. This was revealed by 120,000-year-old fossils from central Germany's Neumark-Nord site (Saxony-Anhalt), analysed by researchers from the University of Potsdam, the MONREPOS Research Center and Museum in Neuwied, and from the Leiden University. Their results have been published in the international journal “iScience”. Modern fallow deer thus represents just a fraction of their Ice Age ancestors' variety. The study highlights how climate and human actions substantially reshaped a once-diverse species and may be informative for conservation action.
Fallow deer, once widespread across central Europe during warm interglacials, retreated south during cold glacial periods. Unique preservation conditions in the lake sediments of Neumark Nord – a fossil biotope near Merseburg in Saxony-Anhalt – enabled this rare temperate-climate DNA recovery.

The research team of the University of Potsdam, the MONREPOS Archaeological Research Centre and Museum for Human Behavioral Evolution in Neuwied, part of the Leibniz-Zentrum für Archäologie (LEIZA), and from the Leiden University (Netherlands), was able to extract ancient DNA from ten fallow deer fossils at Neumark-Nord. Strikingly, the single ancient population from Neumark-Nord exhibits genetic diversity comparable to that of today's fallow deer across their entire Eurasian range, from Spain to Turkey. Modern fallow deer also display unusually low variation compared to relatives like red deer or sambar deer.

Phylogenetic reconstructions show contemporary fallow deer being closely related to the ancient Neumark-Nord lineage.

This pattern strongly suggests that multiple diverse genetic lineages once evolved in or colonized central Europe during the Late Pleistocene, but only a single one survived after the end of the ice age.

Alberto Rocha-Méndez, lead author
Evolutionary Adaptive Genomics
Institute of Biochemistry and Biology
University of Potsdam,
Potsdam, Germany.

Phylogenies date the split between ancient and modern European fallow deer to around 200,000 years ago, amid Middle Pleistocene climate fluctuations. Glacial cooling likely wiped out the diverse northern populations, with survivors only in southern refugia like Anatolia and Balkans. Humans later spread the low-diversity refugial population from Anatolia worldwide during Neolithic, Roman, medieval and modern times.

Due to its deviating anatomy, particularly in antler shape, the fallow deer at Neumark-Nord have long been assigned to their own species or subspecies: Dama (dama) geiselana. The low genetic differentiation to modern fallow deer specimens uncovered in the study, however, rejects a separate status.

The fallow deer once showed high phenotypic variability, but this can be attributed to local adaptation rather than to different genetic lineages.

Lutz Kindler, co-author
Leibniz Zentrum für Archäologie - Neuwied Location
CC Pleistocene and Early Holocene Archaeology
MONREPOS Archaeological Research Centre and Museum for Human Behavioral Evolution,
Neuwied, Germany.
Future work on the full nuclear genome could clarify the species’ demographic history in greater detail.

Background on the excavation site: At the Neumark Nord 1 site, geologist Matthias Thomae discovered a paleolake biotope in 1985, which was excavated and studied by archaeologist Dietrich Mania between 1985 and 1996. According to his findings, there was once a large lake basin at this location, which dates back to the last interglacial 120,000 years ago, known as the Eemian. Between 2004 and 2008, a team from the Leibniz-Zentrum für Archäologie (LEIZA) in Mainz and Leiden University investigated another lake basin at the Neumark-Nord 2 site. Research at both locations revealed a unique environmental archive. The finds are now housed at the State Office for Heritage Management and Archaeology Saxony-Anhalt.

Publication:
Rocha-Méndez, Alberto; Arnold, Patrick; Kindler, Lutz; Gaudzinski-Windheuser, Sabine; Roebroeks, Wil; Scherjon, Fulco; Hofreiter, Michael (2026)
Eemian palaeogenetics demonstrates loss of diversity in modern fallow deer (Dama dama)
iScience 29(6); DOI: 10.1016/j.isci.2026.116204.

Highlights

10 near-complete mitogenomes from 120,000-year-old fallow deer at Neumark-Nord
Ancient local population is as diverse as the entire modern range
Modern Dama dama forms a single clade sister to Eemian lineages
Neumark-Nord morphological variation reflects within species local adaptation

Summary
The European fallow deer (Dama dama) is a widely distributed cervid that has experienced extensive human management since the Neolithic. Although several studies have examined relationships among present-day and Holocene populations, molecular data from Pleistocene fallow deer remain extremely limited, leaving a gap in our understanding of the species’ evolutionary history. Here, we retrieved 10 mitochondrial genomes from a ∼120-thousand-year-old last interglacial (Eemian) fallow deer population from the Neumark-Nord archaeological sites in central Germany. We find that modern European fallow deer throughout their western Eurasian distribution are closely related and form a single clade sister to the Eemian samples. Likewise, modern diversity is low compared to other cervids, whereas this single Eemian assemblage displays comparable levels to that of the entire modern range. Our results suggest that Neumark-Nord mitochondrial lineages were part of broader Late Pleistocene diversity, of which only one part appears to have persisted into the Holocene.

Graphical abstract

Figure 1 Evolutionary relationships between Eemian and modern fallow deer

(A) Secondarily calibrated Bayesian phylogeny of 10 Eemian and 17 modern European fallow deer mitochondrial genomes. The root age was calibrated using the age estimate from the Bayesian mitochondrial species phylogeny. Branch values show posterior probabilities and median 95% HDP values from the best supported model, calibration set 3. Blue node bars represent the 95% credibility intervals of divergence times.

(B) Median joining network of the mitochondrial genomes generated in POPART 1.7 considering positions that are present in all sequences while excluding ambiguities and missing data (alignment length: 7,110 bp), 70 variable sites.

Color of haplotypes depict their origin: ancient Neumark-Nord samples (white), modern Eurasian samples (gray), and hypothetical inferred (black). Node sizes are proportional to the frequencies of the haplotypes. Bars on branches represent the number of mutational steps between the connected haplotypes.

Once again, science has produced evidence that should not exist if creationist mythology were true. There were fallow deer living in Europe tens of thousands of years before the earliest possible date for the alleged biblical creation, and their genomes preserve a history of population change, isolation, loss of genetic diversity, and descent with modification. None of this is consistent with a magical creation event a few thousand years ago, nor with a recent global flood that should have erased such deep-time evidence.

What the study shows is not merely that fallow deer have a long evolutionary history, but that their present genetic condition is the result of ordinary, natural processes: population bottlenecks, founder effects, drift, isolation and selection. These are not speculative “Darwinist” inventions; they are measurable features of real genomes. They leave signatures that can be detected, compared and dated, even in ancient DNA recovered from fossil remains.

Creationists like to pretend that evolution must always mean progress, increasing complexity, or the production of ever more “information”. Real evolution is not obliged to obey that cartoon version. Populations can lose variation, become genetically narrower, and still survive for long periods, at least until environmental change, disease or other pressures expose the cost of that loss. Evolution has no foresight, no benevolent purpose and no protective plan for the future.

The modern fallow deer, then, is not the product of a single act of supernatural manufacture, but of a long and contingent history written in its genome. It is a history of migration, isolation, human interference, chance and survival. As usual, the facts point not to design, but to descent, population history and the blind processes of evolution.

Intellectually honest people would accept that these facts falsify creationist mythology; but not so creationists who will dismiss it so they can continue to cling to demonstrably false beliefs, imagining that changing their mind is a sign of weakness.

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